Lawn mower



' May 29, 1928.

1,671,277 G. S. DONALDSON LAWN MOWER v Filed Aug. 27, 1925 2 Sheets-Sheet l i 4 49if=-- 19 .9 5

mm: m 1 r I J. I 5! l M mm 2 6 WW v May 29, 1928. 1,671,277 G. S. DONALDSON LAWN MOWER Filed Aug. 27, 1925 2 Sheets-Sheet 2 m n m1 0]- 27 Patented May 29, 1928.

GEORGE STANLEY DONALDSON, OF COBU RG, VICTORIA, AUSTRALIA.

LAWN MOWER.

Application filed; August 27, 1925,. Serial No. 52,861,,and in Australia octoberll, 1924.

This invention relates to improvements in lawn-mowers of the type having a set of spiral knives, which are driven by gearing from a travelling or supporting wheel and rotate in contact with the rectilinear edge of a stationary knife placed tangentially in the borders of flower beds and. of garden paths.

A further object is to provide a lawnmower having clutch mechanism so' arranged and operating that in the retractive or reverse movements of the lawn-mower, the gear drive from the travelling or supporting wheel is not actuated and the knives are not rotated, thus reducing wear and increasing the durability of the machine and its integers. r

A still further object is to provide improved mountings for the knifespindle and the trailing roller whereby line adjustments of these parts can be conveniently made for the purpose of accurately regulating the depth of cut by the knives of the machine.

With these and other objects in view, the invention consists of the features of con struction, combination and arrangement hereinafter fully described, reference being had to the accompanying drawings, wherein g v Figure 1 is a view in side elevation of a lawn-mower according to the invention, the cover plate of the near side frame or check being removed for clearness of illustration.

Figure 2 is a view in plan of the lawnmower.

Figure 3 is a View in elevation of the near side frame or check of the machine.

Figure 4 is a plan of'Figure 3.

Figure 5 is a view in elevation of the offside frame or cheek of the machine viewed from the interior.

Figure 6 is a plan of Figure 5.

Figure 7 is a sectional elevation of part of one of the travelling or supporting Wheels.

Figure 8 is a view in section on line 61-6; of Figure 7 illustrating the clutch arrange- 55 ment in a travelling or supporting wheel.

Figure 9' is adetail view illustrating the adjustable mounting of the knife-spindle.

The improved lawn-mower has a near side frame or check 2 and an offside frame or check 3, both of skeleton formation and constructed of cast-metal. The side frame 2, which has a cover plate 4 detachz'rblyv bolted thereto, isdesigned to provide a gear case wherein gear wheels of approved ratios are housed. The frames 2 and 3 are rigidly secured together at required distance apart by transverse tie-bolts 5 passing through apertured bosses 6. forme'd on the inner surfaces of the side frames or cheeks.

A transverse shaft 7 is journaled at its ropposite ends in bearing bosses 8 that are formed on and project inwardly from the interior surfaces of the side frames or cheeks 2 and 3, and mounted on said shaft are two travelling or supporting wheels 9. These wheels are positioned between the side frames-see Figuref2and in order that their distance apart can be conveniently adjusted when occasion requires, collars 10 slidable on the shaft 7 are arranged on opposite sides of said wheels, and are'locked in adjustedpositions on said shaft by setscrews 11. i

A spur-wheel and meshes with an intermediate spur-wheel 13 revolvable on a short spindle 14, which is secured in a boss 15 formed on theexterior-surface of the near side frame or check 2. The spur wheel 13 in'turn meshes with a pinion 16 formed on the end of a transverse spindle 17 Spider frames 18 are mounted on said spindle- 17, and carried by the spider frames are spiral knives 19, which rotate in contact with .the rectilinear edge of a stationary knife 20 disposed tangentially thereto.

The knives 19 and 20 project on either side beyond the path of the travelling or supporting wheels 9 adj nstably mounted between the side frames 2 and 3, and conee quently the cutting elements mow the sward beyond the line of said wheels. The lawnmower can thereby be effectively employed 12 is fast on the shaft"? for mowing around the edges of lawns, or

the borders of flower beds or garden paths without danger of the travelling wheels coming too close to the edges of lawns or causing injury to flowers or plants.

- Each of the travelling or supporting wheels 9. has a clutch in its boss 21 whereby said Wheels are automatically locked on the shaft 7 in the propelling movements of the machine and rotary motion is imparted from said shaft through the train of gear wheels 12, 13 and 1G to the knife-spindle 17.. Tapering recesses 22 are formed in each of said bosses on opposite sides of its bore eccentrically in relation to the shaft 7, and accommodated in said tapering recesses are friction rollers 23. These rollers jam between the narrow portions of the recesses and the shaft during the fervvardunovemerits imparted to the lawn-mower, but on the retractiveor reverse movements of the machine said friction rollers are caused to enter the wider portions of the recesses Within which theynow fit loosely; and the Wheels 9 are permitted to revolve on said shaft in opposite direction whereby motion is not transmitted to said gear Wheels and the spindle carrying the spiral knives. By the ar angementof the clutch mechanism on the shaft 7 carrying the travelling'or supporting wheels, the gears are not rotated during thQbilCkWflICl or reverse movements of the lawn-mower as is the casein la'vvn-nioWers of general construction wherein the clutch is on the knife-spindle of the machine, and as a result the driving gear is subjected to considerably less Wear.

Half-bearings 24; are formed in the side frames or cheeks 2 and 3 and revolvably ac commodate the opposite ends of'the knifespindle 17L Bearing caps 25 are fitted around the upper portions of the spindle ends and are secured in position by setscrews 26 fitted in lugs 27 formed on said side frames or cheeks. Adjustmentof these set-screws is effected to provide forwear of the half-bearings 24 and the knife-spind1e17. i y a a The stationary knife 20 isdetachably fastened toa transverse bar 28, which is secured. by screws 29 at'its oppositeends to brackets or ledges 30 on the interior surfaces of the side frames 2 and 3. The said transary knife relatively to the spiral knives 19,

when the screws are again tightened to lock the lmife-carrrying bar in these'lected posi tion.

A. t'ailing roller 33 is revolvably support ed by. the lower ends of arms 34 that are se cured by bolts 35 passed 'thrdughelongated slots 36 in the side frames or cheeks Q'and By rotating the 3. The upper ends of the arms '3t are rounded and fit snugly into semi circular recesses in lugs 37 formed at the rear ends of said side frames orcheeks, thus facilitating the pivotal movement of said arms when the elevation of the trailing roller is being adjusted as provided for bysaid slots 36. ThelaWn-mower handle 38 is fastenedto a metal bow frame or yoke 39 having its ends pivoted on bosses 'tOthat are formed on the inner surfaces of the side frames or checks 2 and 3. lVhat I do, claim is': p

A lawn-mower having side frames, "a rotating knifemounted in said frames,'a trans verse bar arrangedbetween the frames, semi circular lugs on the ends of said bar, semi GEORGE s. DONALDSON. 

